Fig. 5From: Upregulation of Ca2+-binding proteins contributes to VTA dopamine neuron survival in the early phases of Alzheimer’s disease in Tg2576 miceOverexpression of CB and CR in DA neurons of the Tg2576 VTA. A. Representative confocal image of coronal midbrain section showing TH+ (in red) together with Calbindin (CB+) or Calretinin (CR+) (both in green; scale: 100 μm). B. Stereological quantification of TH+ neurons co-expressing Ca2+-binding proteins (CB or CR) in the VTA of WT and Tg2576 mice of 3- and 6- months of age. TH+CB+ (3 months: WT: n = 6; Tg2576: n = 6; 6 months: WT: n = 4; Tg2576: n = 5 mice. Two-way ANOVA for Genotype vs Age: Interaction: F1,17 = 2.343, p = 0.1443; Age: F1,17 = 1.625, p = 0.2196; Genotype: F1,17 = 20.72, p = 0.0003. WT 3 m vs Tg2576 3 m: Unpaired t-test: *p = 0.0447; WT 6 m vs Tg2576 6 m: Unpaired t-test: **p = 0.0048; Tg2576 3 m vs Tg2576 6 m: Unpaired t-test: **p = 0.0067). TH+CR+ (3 months: WT: n = 4; Tg2576: n = 5; 6 months: WT: n = 5; Tg2576: n = 7 mice. Two-way ANOVA for Genotype vs Age: Interaction: F1,17 = 0.834, p = 0.3714; Genotype: F1,17 = 22.66, p = 0.0002; Age: F1,17 = 22.6, p = 0.0002; WT 3 m vs Tg2576 3 m: *p = 0.0352; WT 6 m vs Tg2576 6 m: **p = 0.0017; Tg2576 3 m vs Tg2576 6 m: ***p = 0.0005). C. Representative western blots from the midbrain of 1-, 3- and 6-month-old WT and Tg2576 mice, and plots showing the levels (expressed as % of WT) of CB (left panel) or CR (right panel) normalized to Actin as loading control. CB: 1 month: n = 5 mice per genotype; 3 months: WT: n = 9; Tg2576: n = 7 mice; Unpaired t-test: *p = 0.0156; 6-months: WT: n = 12; Tg2576: n = 10 mice. CR: 1 month: n = 5 mice per genotype; 3 months: WT: n = 8; Tg2576: n = 9; 6-months: WT: n = 10; Tg2576: n = 11; Unpaired t-test: *p = 0.0228. D-E. Panels show the analysis of confocal Z-stack double immunofluorescent labelling for TH (blue) and CB (D) or CR (E; both in green) in the VTA of coronal sections from 1-, 3- and 6-months-old WT and Tg2576 mice (scale: 20 μm). Box and whisker plots show the densitometric analysis of CB and CR levels in VTA TH+ neurons (D. 1 months-old: WT n = 6 mice, Tg2576 n = 5 mice; 3 months-old: n = 6 mice per genotype; Welch’s: **p = 0.0046; 6 months-old: WT n = 6 mice, Tg2576 n = 5 mice. E. 1 months-old: n = 4 mice per genotype; 3 months-old: WT n = 5 mice, Tg2576 n = 4 mice; Unpaired t-test: *p = 0. 0263. 6 months-old: WT n = 6 mice, Tg2576 n = 5 mice). F. The plot shows the amount of free [Ca2+] expressed as 340/380 ratio of Fura-2 in the PN o 3-month-old WT and Tg2576 mice (WT: n = 9 neurons,3 mice; Tg2576: n = 10 neurons, 3 mice; Welch’s t-test, **p = 0.0024). G. Representative confocal images of TUNEL-negative (TUNEL-) and -positive (TUNEL+) dopaminergic neurons expressing CB from the VTA of 3-month-old Tg2576 mice (scale bar: 10 μm). The graph shows densitometric levels of CB in TUNEL- and TUNEL+ neurons (TUNEL-: n = 19 neurons; 3 mice; TUNEL+: n = 16 neurons; 3 mice; Unpaired t-test: *p = 0.0141)Back to article page